mirror of
https://github.com/python/cpython.git
synced 2025-08-04 08:59:19 +00:00

Add nonlocal_stmt to Grammar and Nonlocal node to AST. They both parallel the definitions for globals. The symbol table treats variables declared as nonlocal just like variables that are free implicitly. This change is missing the language spec changes, but makes some decisions about what the spec should say via the unittests. The PEP is silent on a number of decisions, so we should review those before claiming that nonlocal is complete. Thomas Wouters made the grammer and ast changes. Jeremy Hylton added the symbol table changes and the tests. Pete Shinners and Neal Norwitz helped review the code.
647 lines
14 KiB
Python
647 lines
14 KiB
Python
import unittest
|
|
from test.test_support import check_syntax_error, run_unittest
|
|
|
|
import warnings
|
|
warnings.filterwarnings("ignore", r"import \*", SyntaxWarning, "<test string>")
|
|
warnings.filterwarnings("ignore", r"import \*", SyntaxWarning, "<string>")
|
|
|
|
class ScopeTests(unittest.TestCase):
|
|
|
|
def testSimpleNesting(self):
|
|
|
|
def make_adder(x):
|
|
def adder(y):
|
|
return x + y
|
|
return adder
|
|
|
|
inc = make_adder(1)
|
|
plus10 = make_adder(10)
|
|
|
|
self.assertEqual(inc(1), 2)
|
|
self.assertEqual(plus10(-2), 8)
|
|
|
|
def testExtraNesting(self):
|
|
|
|
def make_adder2(x):
|
|
def extra(): # check freevars passing through non-use scopes
|
|
def adder(y):
|
|
return x + y
|
|
return adder
|
|
return extra()
|
|
|
|
inc = make_adder2(1)
|
|
plus10 = make_adder2(10)
|
|
|
|
self.assertEqual(inc(1), 2)
|
|
self.assertEqual(plus10(-2), 8)
|
|
|
|
def testSimpleAndRebinding(self):
|
|
|
|
def make_adder3(x):
|
|
def adder(y):
|
|
return x + y
|
|
x = x + 1 # check tracking of assignment to x in defining scope
|
|
return adder
|
|
|
|
inc = make_adder3(0)
|
|
plus10 = make_adder3(9)
|
|
|
|
self.assertEqual(inc(1), 2)
|
|
self.assertEqual(plus10(-2), 8)
|
|
|
|
def testNestingGlobalNoFree(self):
|
|
|
|
def make_adder4(): # XXX add exta level of indirection
|
|
def nest():
|
|
def nest():
|
|
def adder(y):
|
|
return global_x + y # check that plain old globals work
|
|
return adder
|
|
return nest()
|
|
return nest()
|
|
|
|
global_x = 1
|
|
adder = make_adder4()
|
|
self.assertEqual(adder(1), 2)
|
|
|
|
global_x = 10
|
|
self.assertEqual(adder(-2), 8)
|
|
|
|
def testNestingThroughClass(self):
|
|
|
|
def make_adder5(x):
|
|
class Adder:
|
|
def __call__(self, y):
|
|
return x + y
|
|
return Adder()
|
|
|
|
inc = make_adder5(1)
|
|
plus10 = make_adder5(10)
|
|
|
|
self.assertEqual(inc(1), 2)
|
|
self.assertEqual(plus10(-2), 8)
|
|
|
|
def testNestingPlusFreeRefToGlobal(self):
|
|
|
|
def make_adder6(x):
|
|
global global_nest_x
|
|
def adder(y):
|
|
return global_nest_x + y
|
|
global_nest_x = x
|
|
return adder
|
|
|
|
inc = make_adder6(1)
|
|
plus10 = make_adder6(10)
|
|
|
|
self.assertEqual(inc(1), 11) # there's only one global
|
|
self.assertEqual(plus10(-2), 8)
|
|
|
|
def testNearestEnclosingScope(self):
|
|
|
|
def f(x):
|
|
def g(y):
|
|
x = 42 # check that this masks binding in f()
|
|
def h(z):
|
|
return x + z
|
|
return h
|
|
return g(2)
|
|
|
|
test_func = f(10)
|
|
self.assertEqual(test_func(5), 47)
|
|
|
|
def testMixedFreevarsAndCellvars(self):
|
|
|
|
def identity(x):
|
|
return x
|
|
|
|
def f(x, y, z):
|
|
def g(a, b, c):
|
|
a = a + x # 3
|
|
def h():
|
|
# z * (4 + 9)
|
|
# 3 * 13
|
|
return identity(z * (b + y))
|
|
y = c + z # 9
|
|
return h
|
|
return g
|
|
|
|
g = f(1, 2, 3)
|
|
h = g(2, 4, 6)
|
|
self.assertEqual(h(), 39)
|
|
|
|
def testFreeVarInMethod(self):
|
|
|
|
def test():
|
|
method_and_var = "var"
|
|
class Test:
|
|
def method_and_var(self):
|
|
return "method"
|
|
def test(self):
|
|
return method_and_var
|
|
def actual_global(self):
|
|
return str("global")
|
|
def str(self):
|
|
return str(self)
|
|
return Test()
|
|
|
|
t = test()
|
|
self.assertEqual(t.test(), "var")
|
|
self.assertEqual(t.method_and_var(), "method")
|
|
self.assertEqual(t.actual_global(), "global")
|
|
|
|
method_and_var = "var"
|
|
class Test:
|
|
# this class is not nested, so the rules are different
|
|
def method_and_var(self):
|
|
return "method"
|
|
def test(self):
|
|
return method_and_var
|
|
def actual_global(self):
|
|
return str("global")
|
|
def str(self):
|
|
return str(self)
|
|
|
|
t = Test()
|
|
self.assertEqual(t.test(), "var")
|
|
self.assertEqual(t.method_and_var(), "method")
|
|
self.assertEqual(t.actual_global(), "global")
|
|
|
|
def testRecursion(self):
|
|
|
|
def f(x):
|
|
def fact(n):
|
|
if n == 0:
|
|
return 1
|
|
else:
|
|
return n * fact(n - 1)
|
|
if x >= 0:
|
|
return fact(x)
|
|
else:
|
|
raise ValueError, "x must be >= 0"
|
|
|
|
self.assertEqual(f(6), 720)
|
|
|
|
|
|
def testUnoptimizedNamespaces(self):
|
|
|
|
check_syntax_error(self, """\
|
|
def unoptimized_clash1(strip):
|
|
def f(s):
|
|
from string import *
|
|
return strip(s) # ambiguity: free or local
|
|
return f
|
|
""")
|
|
|
|
check_syntax_error(self, """\
|
|
def unoptimized_clash2():
|
|
from string import *
|
|
def f(s):
|
|
return strip(s) # ambiguity: global or local
|
|
return f
|
|
""")
|
|
|
|
check_syntax_error(self, """\
|
|
def unoptimized_clash2():
|
|
from string import *
|
|
def g():
|
|
def f(s):
|
|
return strip(s) # ambiguity: global or local
|
|
return f
|
|
""")
|
|
|
|
check_syntax_error(self, """\
|
|
def f(x):
|
|
def g():
|
|
return x
|
|
del x # can't del name
|
|
""")
|
|
|
|
check_syntax_error(self, """\
|
|
def f():
|
|
def g():
|
|
from string import *
|
|
return strip # global or local?
|
|
""")
|
|
|
|
# and verify a few cases that should work
|
|
|
|
exec("""
|
|
def noproblem1():
|
|
from string import *
|
|
f = lambda x:x
|
|
|
|
def noproblem2():
|
|
from string import *
|
|
def f(x):
|
|
return x + 1
|
|
|
|
def noproblem3():
|
|
from string import *
|
|
def f(x):
|
|
global y
|
|
y = x
|
|
""")
|
|
|
|
def testLambdas(self):
|
|
|
|
f1 = lambda x: lambda y: x + y
|
|
inc = f1(1)
|
|
plus10 = f1(10)
|
|
self.assertEqual(inc(1), 2)
|
|
self.assertEqual(plus10(5), 15)
|
|
|
|
f2 = lambda x: (lambda : lambda y: x + y)()
|
|
inc = f2(1)
|
|
plus10 = f2(10)
|
|
self.assertEqual(inc(1), 2)
|
|
self.assertEqual(plus10(5), 15)
|
|
|
|
f3 = lambda x: lambda y: global_x + y
|
|
global_x = 1
|
|
inc = f3(None)
|
|
self.assertEqual(inc(2), 3)
|
|
|
|
f8 = lambda x, y, z: lambda a, b, c: lambda : z * (b + y)
|
|
g = f8(1, 2, 3)
|
|
h = g(2, 4, 6)
|
|
self.assertEqual(h(), 18)
|
|
|
|
def testUnboundLocal(self):
|
|
|
|
def errorInOuter():
|
|
print(y)
|
|
def inner():
|
|
return y
|
|
y = 1
|
|
|
|
def errorInInner():
|
|
def inner():
|
|
return y
|
|
inner()
|
|
y = 1
|
|
|
|
try:
|
|
errorInOuter()
|
|
except UnboundLocalError:
|
|
pass
|
|
else:
|
|
self.fail()
|
|
|
|
try:
|
|
errorInInner()
|
|
except NameError:
|
|
pass
|
|
else:
|
|
self.fail()
|
|
|
|
# test for bug #1501934: incorrect LOAD/STORE_GLOBAL generation
|
|
exec("""
|
|
global_x = 1
|
|
def f():
|
|
global_x += 1
|
|
try:
|
|
f()
|
|
except UnboundLocalError:
|
|
pass
|
|
else:
|
|
fail('scope of global_x not correctly determined')
|
|
""", {'fail': self.fail})
|
|
|
|
def testComplexDefinitions(self):
|
|
|
|
def makeReturner(*lst):
|
|
def returner():
|
|
return lst
|
|
return returner
|
|
|
|
self.assertEqual(makeReturner(1,2,3)(), (1,2,3))
|
|
|
|
def makeReturner2(**kwargs):
|
|
def returner():
|
|
return kwargs
|
|
return returner
|
|
|
|
self.assertEqual(makeReturner2(a=11)()['a'], 11)
|
|
|
|
def makeAddPair((a, b)):
|
|
def addPair((c, d)):
|
|
return (a + c, b + d)
|
|
return addPair
|
|
|
|
self.assertEqual(makeAddPair((1, 2))((100, 200)), (101,202))
|
|
|
|
def testScopeOfGlobalStmt(self):
|
|
# Examples posted by Samuele Pedroni to python-dev on 3/1/2001
|
|
|
|
exec("""\
|
|
# I
|
|
x = 7
|
|
def f():
|
|
x = 1
|
|
def g():
|
|
global x
|
|
def i():
|
|
def h():
|
|
return x
|
|
return h()
|
|
return i()
|
|
return g()
|
|
self.assertEqual(f(), 7)
|
|
self.assertEqual(x, 7)
|
|
|
|
# II
|
|
x = 7
|
|
def f():
|
|
x = 1
|
|
def g():
|
|
x = 2
|
|
def i():
|
|
def h():
|
|
return x
|
|
return h()
|
|
return i()
|
|
return g()
|
|
self.assertEqual(f(), 2)
|
|
self.assertEqual(x, 7)
|
|
|
|
# III
|
|
x = 7
|
|
def f():
|
|
x = 1
|
|
def g():
|
|
global x
|
|
x = 2
|
|
def i():
|
|
def h():
|
|
return x
|
|
return h()
|
|
return i()
|
|
return g()
|
|
self.assertEqual(f(), 2)
|
|
self.assertEqual(x, 2)
|
|
|
|
# IV
|
|
x = 7
|
|
def f():
|
|
x = 3
|
|
def g():
|
|
global x
|
|
x = 2
|
|
def i():
|
|
def h():
|
|
return x
|
|
return h()
|
|
return i()
|
|
return g()
|
|
self.assertEqual(f(), 2)
|
|
self.assertEqual(x, 2)
|
|
|
|
# XXX what about global statements in class blocks?
|
|
# do they affect methods?
|
|
|
|
x = 12
|
|
class Global:
|
|
global x
|
|
x = 13
|
|
def set(self, val):
|
|
x = val
|
|
def get(self):
|
|
return x
|
|
|
|
g = Global()
|
|
self.assertEqual(g.get(), 13)
|
|
g.set(15)
|
|
self.assertEqual(g.get(), 13)
|
|
""")
|
|
|
|
def testLeaks(self):
|
|
|
|
class Foo:
|
|
count = 0
|
|
|
|
def __init__(self):
|
|
Foo.count += 1
|
|
|
|
def __del__(self):
|
|
Foo.count -= 1
|
|
|
|
def f1():
|
|
x = Foo()
|
|
def f2():
|
|
return x
|
|
f2()
|
|
|
|
for i in range(100):
|
|
f1()
|
|
|
|
self.assertEqual(Foo.count, 0)
|
|
|
|
def testClassAndGlobal(self):
|
|
|
|
exec("""\
|
|
def test(x):
|
|
class Foo:
|
|
global x
|
|
def __call__(self, y):
|
|
return x + y
|
|
return Foo()
|
|
|
|
x = 0
|
|
self.assertEqual(test(6)(2), 8)
|
|
x = -1
|
|
self.assertEqual(test(3)(2), 5)
|
|
|
|
looked_up_by_load_name = False
|
|
class X:
|
|
# Implicit globals inside classes are be looked up by LOAD_NAME, not
|
|
# LOAD_GLOBAL.
|
|
locals()['looked_up_by_load_name'] = True
|
|
passed = looked_up_by_load_name
|
|
|
|
self.assert_(X.passed)
|
|
""")
|
|
|
|
def testLocalsFunction(self):
|
|
|
|
def f(x):
|
|
def g(y):
|
|
def h(z):
|
|
return y + z
|
|
w = x + y
|
|
y += 3
|
|
return locals()
|
|
return g
|
|
|
|
d = f(2)(4)
|
|
self.assert_('h' in d)
|
|
del d['h']
|
|
self.assertEqual(d, {'x': 2, 'y': 7, 'w': 6})
|
|
|
|
def testBoundAndFree(self):
|
|
# var is bound and free in class
|
|
|
|
def f(x):
|
|
class C:
|
|
def m(self):
|
|
return x
|
|
a = x
|
|
return C
|
|
|
|
inst = f(3)()
|
|
self.assertEqual(inst.a, inst.m())
|
|
|
|
def testInteractionWithTraceFunc(self):
|
|
|
|
import sys
|
|
def tracer(a,b,c):
|
|
return tracer
|
|
|
|
def adaptgetter(name, klass, getter):
|
|
kind, des = getter
|
|
if kind == 1: # AV happens when stepping from this line to next
|
|
if des == "":
|
|
des = "_%s__%s" % (klass.__name__, name)
|
|
return lambda obj: getattr(obj, des)
|
|
|
|
class TestClass:
|
|
pass
|
|
|
|
sys.settrace(tracer)
|
|
adaptgetter("foo", TestClass, (1, ""))
|
|
sys.settrace(None)
|
|
|
|
self.assertRaises(TypeError, sys.settrace)
|
|
|
|
def testEvalExecFreeVars(self):
|
|
|
|
def f(x):
|
|
return lambda: x + 1
|
|
|
|
g = f(3)
|
|
self.assertRaises(TypeError, eval, g.__code__)
|
|
|
|
try:
|
|
exec(g.__code__, {})
|
|
except TypeError:
|
|
pass
|
|
else:
|
|
self.fail("exec should have failed, because code contained free vars")
|
|
|
|
def testListCompLocalVars(self):
|
|
|
|
try:
|
|
print(bad)
|
|
except NameError:
|
|
pass
|
|
else:
|
|
print("bad should not be defined")
|
|
|
|
def x():
|
|
[bad for s in 'a b' for bad in s.split()]
|
|
|
|
x()
|
|
try:
|
|
print(bad)
|
|
except NameError:
|
|
pass
|
|
|
|
def testEvalFreeVars(self):
|
|
|
|
def f(x):
|
|
def g():
|
|
x
|
|
eval("x + 1")
|
|
return g
|
|
|
|
f(4)()
|
|
|
|
def testNonLocalFunction(self):
|
|
|
|
def f(x):
|
|
def inc():
|
|
nonlocal x
|
|
x += 1
|
|
return x
|
|
def dec():
|
|
nonlocal x
|
|
x -= 1
|
|
return x
|
|
return inc, dec
|
|
|
|
inc, dec = f(0)
|
|
self.assertEqual(inc(), 1)
|
|
self.assertEqual(inc(), 2)
|
|
self.assertEqual(dec(), 1)
|
|
self.assertEqual(dec(), 0)
|
|
|
|
def testNonLocalMethod(self):
|
|
|
|
def f(x):
|
|
class c:
|
|
def inc(self):
|
|
nonlocal x
|
|
x += 1
|
|
return x
|
|
def dec(self):
|
|
nonlocal x
|
|
x -= 1
|
|
return x
|
|
return c()
|
|
|
|
c = f(0)
|
|
self.assertEqual(c.inc(), 1)
|
|
self.assertEqual(c.inc(), 2)
|
|
self.assertEqual(c.dec(), 1)
|
|
self.assertEqual(c.dec(), 0)
|
|
|
|
def testNonLocalClass(self):
|
|
|
|
def f(x):
|
|
class c:
|
|
nonlocal x
|
|
x += 1
|
|
def get(self):
|
|
return x
|
|
return c()
|
|
|
|
c = f(0)
|
|
self.assertEqual(c.get(), 1)
|
|
self.assert_("x" not in c.__class__.__dict__)
|
|
|
|
|
|
def testNonLocalGenerator(self):
|
|
|
|
def f(x):
|
|
def g(y):
|
|
nonlocal x
|
|
for i in range(y):
|
|
x += 1
|
|
yield x
|
|
return g
|
|
|
|
g = f(0)
|
|
self.assertEqual(list(g(5)), [1, 2, 3, 4, 5])
|
|
|
|
def testNestedNonLocal(self):
|
|
|
|
def f(x):
|
|
def g():
|
|
nonlocal x
|
|
x -= 2
|
|
def h():
|
|
nonlocal x
|
|
x += 4
|
|
return x
|
|
return h
|
|
return g
|
|
|
|
g = f(1)
|
|
h = g()
|
|
self.assertEqual(h(), 3)
|
|
|
|
|
|
def test_main():
|
|
run_unittest(ScopeTests)
|
|
|
|
if __name__ == '__main__':
|
|
test_main()
|